Multichoice i made an overpayment, please pay me back

I made an overpayment in error and I have been battling to get my money reimbursed. I called Multichoice for the umpteenth time today and was told that the lady who helped me last time didn't attach my supporting documents to my query and I'd have to restart the process. The lady would not say how long it will take for me to get my money back. Surely there's a policy that governs such? I need to be paid back asaptually.